This paper is based on observational data collected during my PhD work. I looked at the effects of wetland size, water presence, shape, and landscape location on the diversity of bird communities on highly transformed, irrigated, agricultural wetlands. We found that wetlands with irregular shapes, regular presence of water, and or large sizes hosted the highest diversity. We then recommended to design wetlands with these elements when restoring or creating wetlands in agricultural watersheds. These wetlands could also be designed to achieve other goals, particularly improving water quality with specific retention times, and reducing soil salinity, by facilitating the accumulation of organic matter in the soil. These design recommendations where used in an EU LIFE project, used to create and restore dozens of wetlands in the region where the research was carried out.